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cleanup all cache adapter documentation, extend redis docs
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‎components/cache.rst

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single: Performance
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single: Components; Cache
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.. _`cache-component`:
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68
The Cache Component
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===================
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‎components/cache/adapters/apcu_adapter.rst

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single: Cache Pool
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single: APC Cache, APCu Cache
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.. _apcu-adapter:
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APCu Cache Adapter
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==================
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This adapter can increase the application performance very significantly,
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because contents are cached in the shared memory of your server, which is much
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faster than the file system. It requires to have installed and enabled the PHP
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APCu extension. It's not recommended to use it when performing lots of write and
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delete operations because it produces fragmentation in the APCu memory that can
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degrade performance significantly::
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This adapter is a high-performance, shared memory cache. It can increase the
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application performance very significantly because the cache contents are
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stored in the shared memory of your server, a component that is much faster than
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others, such as the file system.
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.. caution::
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**Requirement:** The `APCu extension`_ must be installed and active to use
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this adapter.
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This adapter can be provided an optional namespace string as its first parameter, a
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default cache lifetime as its second parameter, and a version string as its third
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parameter::
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use Symfony\Component\Cache\Adapter\ApcuAdapter;
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$cache = new ApcuAdapter(
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// the string prefixed to the keys of the items stored in this cache
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// a string prefixed to the keys of the items stored in this cache
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$namespace = '',
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// in seconds; applied to cache items that don't define their own lifetime
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// 0 means to store the cache items indefinitely (i.e. until the APC memory is deleted)
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// the default lifetime (in seconds) for cache items that do not define their
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// own lifetime, with a value 0 causing items to be stored indefinitely (i.e.
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// until the APCu memory is cleared)
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$defaultLifetime = 0,
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// if present, this string is added to the namespace to simplify the
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// invalidation of the entire cache (e.g. when deploying the application)
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// when set, all keys prefixed by $namespace can be invalidated by changing
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// this $version string
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$version = null
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);
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.. caution::
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It is *not* recommended to use this adapter when performing a large number of
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write and delete operations, as these operations result in fragmentation of the
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APCu memory, resulting in *significantly* degraded performance.
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.. tip::
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Note that this adapters CRUD operations are specific to the PHP SAPI it is running
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under. This means adding a cache item using the CLI will not result in the item
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appearing under FPM. Likewise, deletion of an item using CGI will not result in the
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item being deleted under the CLI.
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.. _`APCu extension`: https://pecl.php.net/package/APCu

‎components/cache/adapters/array_cache_adapter.rst

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Array Cache Adapter
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===================
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This adapter is only useful for testing purposes because contents are stored in
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memory and not persisted in any way. Besides, some features explained later are
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not available, such as the deferred saves::
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Generally, this adapter is useful for testing purposes, as its contents are stored in memory
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and not persisted outside the running PHP process in any way. It can also be useful while
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warming up caches, due to the :method:`Symfony\\Component\\Cache\\Adapter\\ArrayAdapter::getValues`
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method.
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This adapter can be passed a default cache lifetime as its first parameter, and a boolean that
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toggles serialization as its second parameter::
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use Symfony\Component\Cache\Adapter\ArrayAdapter;
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$cache = new ArrayAdapter(
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// in seconds; applied to cache items that don't define their own lifetime
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// 0 means to store the cache items indefinitely (i.e. until the current PHP process finishes)
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// the default lifetime (in seconds) for cache items that do not define their
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// own lifetime, with a value 0 causing items to be stored indefinitely (i.e.
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// until the current PHP process finishes)
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$defaultLifetime = 0,
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// if ``true``, the values saved in the cache are serialized before storing them
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$storeSerialized = true
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);

‎components/cache/adapters/chain_adapter.rst

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Chain Cache Adapter
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===================
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This adapter allows to combine any number of the previous adapters. Cache items
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are fetched from the first adapter which contains them. Besides, cache items are
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saved in all the given adapters, so this is a simple way of creating a cache
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replication::
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This adapter allows to combine any number of the other available cache adapters.
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Cache items are fetched from the first adapter which contains them and cache items are
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saved in all the given adapters. This offers a simple way of creating a layered cache.
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This adapter expects an array of adapters as its first parameter, and optionally a
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maximum cache lifetime as its second parameter::
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use Symfony\Component\Cache\Adapter\ApcuAdapter;
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use Symfony\Component\Cache\Adapter\ChainAdapter;
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use Symfony\Component\Cache\Adapter\FilesystemAdapter;
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$apcCache = new ApcuAdapter();
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$fileCache = new FilesystemAdapter();
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$cache = new ChainAdapter(array(
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// The ordered list of adapters used to fetch cached items
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array $adapters,
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// The max lifetime of items propagated from lower adapters to upper ones
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$maxLifetime = 0
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));
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.. note::
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$cache = new ChainAdapter(array($apcCache, $fileCache));
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When an item is not found in the first adapters but is found in the next ones, this
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adapter ensures that the fetched item is saved in all the adapters where it was
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previously missing.
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The following shows how to create a chain adapter instance using the fastest and slowest
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storage engines, :class:`Symfony\\Component\\Cache\\Adapter\\ApcuAdapter` and
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:class:`Symfony\\Component\\Cache\\Adapter\\FilesystemAdapter`, respectfully::
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use Symfony\Component\Cache\Adapter\ApcuAdapter;
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use Symfony\Component\Cache\Adapter\ChainAdapter;
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use Symfony\Component\Cache\Adapter\FilesystemAdapter;
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When an item is not found in the first adapters but is found in the next ones,
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the ``ChainAdapter`` ensures that the fetched item is saved in all the adapters
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where it was missing. Since it's not possible to know the expiry date and time
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of a cache item, the second optional argument of ``ChainAdapter`` is the default
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lifetime applied to those cache items (by default it's ``0``).
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$cache = new ChainAdapter(array(
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new ApcuAdapter(),
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new FilesystemAdapter(),
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));

‎components/cache/adapters/doctrine_adapter.rst

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single: Cache Pool
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single: Doctrine Cache
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.. _`doctrine-adapter`:
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Doctrine Cache Adapter
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======================
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This adapter wraps any `Doctrine Cache`_ provider so you can use them in your
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application as if they were Symfony Cache adapters::
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This adapter wraps any class extending the `Doctrine Cache`_ abstract provider, allowing
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you to use these providers in your application as if they were Symfony Cache adapters.
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This adapter expects a ``\Doctrine\Common\Cache\CacheProvider`` instance as its first
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parameter, and optionally a namespace and default cache lifetime as its second and
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third parameters::
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use Doctrine\Common\Cache\CacheProvider;
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use Doctrine\Common\Cache\SQLite3Cache;
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use Symfony\Component\Cache\Adapter\DoctrineAdapter;
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$sqliteDatabase = new \SQLite3(__DIR__.'/cache/data.sqlite');
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$doctrineCache = new SQLite3Cache($sqliteDatabase, 'tableName');
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$symfonyCache = new DoctrineAdapter($doctrineCache);
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$provider = new SQLite3Cache(new \SQLite3(__DIR__.'/cache/data.sqlite'), 'youTableName');
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$symfonyCache = new DoctrineAdapter(
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// a cache provider instance
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CacheProvider $provider,
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// a string prefixed to the keys of the items stored in this cache
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$namespace = '',
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This adapter also defines two optional arguments called ``namespace`` (default:
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``''``) and ``defaultLifetime`` (default: ``0``) and adapts them to make them
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work in the underlying Doctrine cache.
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// the default lifetime (in seconds) for cache items that do not define their
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// own lifetime, with a value 0 causing items to be stored indefinitely (i.e.
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// until the database table is truncated or its rows are otherwise deleted)
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$defaultLifetime = 0
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);
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.. _`Doctrine Cache`: https://github.com/doctrine/cache

‎components/cache/adapters/filesystem_adapter.rst

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========================
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This adapter is useful when you want to improve the application performance but
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can't install tools like APCu or Redis in the server. This adapter stores the
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contents as regular files in a set of directories on the local file system::
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can't install tools like APCu or Redis on the server. This adapter stores the
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contents as regular files in a set of directories on the local file system.
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This adapter can optionally be provided a namespace, default cache lifetime, and
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directory path, as its first, second, and third parameters::
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use Symfony\Component\Cache\Adapter\FilesystemAdapter;
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$cache = new FilesystemAdapter(
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// the subdirectory of the main cache directory where cache items are stored
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// a string used as the subdirectory of the root cache directory, where cache
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// items will be stored
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$namespace = '',
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// in seconds; applied to cache items that don't define their own lifetime
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// 0 means to store the cache items indefinitely (i.e. until the files are deleted)
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// the default lifetime (in seconds) for cache items that do not define their
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// own lifetime, with a value 0 causing items to be stored indefinitely (i.e.
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// until the files are deleted)
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$defaultLifetime = 0,
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// the main cache directory (the application needs read-write permissions on it)
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// if none is specified, a directory is created inside the system temporary directory
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$directory = null
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);
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.. tip::
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This adapter is generally the *slowest* due to the overhead of file IO. If throughput is paramount,
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the in-memory adapters (such as :ref:`APCu <apcu-adapter>`, :ref:`Memcached <memcached-adapter>`,
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and :ref:`Redis <redis-adapter>`) or the database adapters (such as
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:ref:`Doctrine <doctrine-adapter>` and :ref:`PDO & Doctrine <pdo-doctrine-adapter>`) are recommended.

‎components/cache/adapters/memcached_adapter.rst

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single: Cache Pool
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single: Memcached Cache
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.. _memcached-adapter:
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Memcached Cache Adapter
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=======================
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The Memcached adapter was introduced in Symfony 3.3.
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This adapter stores the values in-memory using one (or more) `Memcached server`_
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instances. Unlike the ACPu adapter, and similarly to the Redis adapter, it is
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not limited to the current server's shared memory; you can store contents
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independent of your PHP environment. The ability to utilize a cluster of servers
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to provide redundancy and/or fail-over is also available.
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instances. Unlike the :ref:`APCu adapter <apcu-adapter>`, and similarly to the
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:ref:`Redis adapter <redis-adapter>`, it is not limited to the current server's
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shared memory; you can store contents independent of your PHP environment.
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The ability to utilize a cluster of servers to provide redundancy and/or fail-over
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is also available.
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.. caution::
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The `Memcached PHP extension`_ as well as a `Memcached server`_ must be
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installed, active, and running to use this adapter.
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**Requirements:** The `Memcached PHP extension`_ as well as a `Memcached server`_
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must be installed, active, and running to use this adapter. Version ``2.2`` or
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greater of the `Memcached PHP extension`_ is required for this adapter.
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This adapter expects a `Memcached`_ instance to be passed as the first
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parameter. A namespace and default cache lifetime can optionally be passed as
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optional username and password (for SASL authentication; it requires that the
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memcached extension was compiled with ``--enable-memcached-sasl``) and an
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optional weight (for prioritizing servers in a cluster; its value is an integer
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between ``0`` and ``100`` which defaults to ``XX``; a higher value means more
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between ``0`` and ``100`` which defaults to ``null``; a higher value means more
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priority).
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Below are common examples of valid DSNs showing a combination of available values::
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expense of more write traffic.
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``recv_timeout`` (type: ``int``, default: ``0``)
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Specifies he amount of time (in microseconds) before timing out during an outgoing socket (read) operation.
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Specifies the amount of time (in microseconds) before timing out during an outgoing socket (read) operation.
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When the ``no_block`` option isn't enabled, this will allow you to still have timeouts on the reading of data.
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Valid option values include ``0`` or *any positive integer*.
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are valid and fit within the design of the protocol being used.
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.. tip::
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Reference the `Memcached extension`_'s `predefined constants`_ documentation
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Reference the `Memcached`_ extension's `predefined constants`_ documentation
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for additional information about the available options.
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.. _`Transmission Control Protocol (TCP)`: https://en.wikipedia.org/wiki/Transmission_Control_Protocol

‎components/cache/adapters/pdo_doctrine_dbal_adapter.rst

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single: Cache Pool
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single: PDO Cache, Doctrine DBAL Cache
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.. _`pdo-doctrine-adapter`:
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PDO & Doctrine DBAL Cache Adapter
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=================================
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The PDO & Doctrine DBAL adapter was introduced in Symfony 3.2.
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This adapter stores the cached items a SQL database accessed through a PDO or a
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Doctrine DBAL connection::
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This adapter stores the cache items in an SQL database. It requires a `PDO`_,
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`Doctrine DBAL Connection`_, or `Data Source Name (DSN)`_ as its first parameter, and
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optionally a namespace, default cache lifetime, and options array as its second,
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third, and forth parameters::
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use Symfony\Component\Cache\Adapter\PdoAdapter;
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$cache = new PdoAdapter(
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// a PDO, a Doctrine DBAL connection or DSN for lazy connecting through PDO
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$databaseConnectionOrDSN,
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// the string prefixed to the keys of the items stored in this cache
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$namespace = '',
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// in seconds; applied to cache items that don't define their own lifetime
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// 0 means to store the cache items indefinitely (i.e. until the database is cleared)
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// the default lifetime (in seconds) for cache items that do not define their
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// own lifetime, with a value 0 causing items to be stored indefinitely (i.e.
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// until the database table is truncated or its rows are otherwise deleted)
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$defaultLifetime = 0,
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// an array of options for configuring the database connection
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$options = array()
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);
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.. tip::
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When passed a `Data Source Name (DSN)`_ string (instead of a database connection
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class instance), the connection will be lazy-loaded when needed.
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.. _`PDO`: http://php.net/manual/en/class.pdo.php
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.. _`Doctrine DBAL Connection`: https://github.com/doctrine/dbal/blob/master/lib/Doctrine/DBAL/Connection.php
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.. _`Data Source Name (DSN)`: https://en.wikipedia.org/wiki/Data_source_name

‎components/cache/adapters/proxy_adapter.rst

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Proxy Cache Adapter
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===================
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This adapter is useful to integrate in your application cache pools not created
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with the Symfony Cache component. As long as those cache pools implement the
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``CacheItemPoolInterface`` interface, this adapter allows you to get items from
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that external cache and save them in the Symfony cache of your application::
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This adapter wraps a `PSR-6`_ compliant `cache item pool interface`_. It is used to integrate
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your application's cache item pool implementation with the Symfony :ref:`Cache Component <cache-component>`
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by consuming any implementation of ``Psr\Cache\CacheItemPoolInterface``.
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This adapter expects a ``Psr\Cache\CacheItemPoolInterface`` instance as its first parameter,
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and optionally a namespace and default cache lifetime as its second and third parameters::
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use Psr\Cache\CacheItemPoolInterface;
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use Symfony\Component\Cache\Adapter\ProxyAdapter;
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// ... create $nonSymfonyCache somehow
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$cache = new ProxyAdapter($nonSymfonyCache);
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$psr6CachePool = \\ create your own cache pool instance that implements the PSR-6
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\\ interface `CacheItemPoolInterface`
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$cache = new ProxyAdapter(
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// a cache pool instance
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CacheItemPoolInterface $psr6CachePool,
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// a string prefixed to the keys of the items stored in this cache
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$namespace = '',
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// the default lifetime (in seconds) for cache items that do not define their
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// own lifetime, with a value 0 causing items to be stored indefinitely (i.e.
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// until the cache is cleared)
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$defaultLifetime = 0
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);
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The adapter accepts two additional optional arguments: the namespace (``''`` by
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default) and the default lifetime (``0`` by default).
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.. _`PSR-6`: http://www.php-fig.org/psr/psr-6/
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.. _`cache item pool interface`: http://www.php-fig.org/psr/psr-6/#cacheitempoolinterface

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